1. Field of the Invention
The present invention relates to a surveillance system equipped with a plurality of surveillance cameras and a surveillance camera used in the system, particularly, to a surveillance system that performs surveillance of moving persons by way of combination of a plurality of cameras and a camera used in the system.
2. Description of the Related Art
A variety of systems that performs automated surveillance of persons who enters or exits a building have been developed.
“JP P2000-163600A1” discloses a surveillance system that extracts the characteristics of the face of a person from the image picked up by a surveillance camera and compares the characteristics with facemasks registered in a database. In this system, control means for analyzing an image signal from a surveillance camera recognizes the position of the face of a person shot by the surveillance camera and controls the panning, tilting and zooming operations of the surveillance camera to track the motion of the face. The control means then extracts the contour lines of the eyes, nose, mouth and eyebrows, extracts the feature points of the face based on the contour lines, and compares with facemasks registered in the database.
“JP PH06-325180A1” discloses a system for tracking and monitoring a movable object by using a plurality of cameras. As shown in FIG. 13, this system has a plurality of surveillance camera units 1, a monitor unit 6 for displaying images from the surveillance camera units 1, and a camera switching unit 2 for switching between the surveillance camera units 1 to change the image output to the monitor unit 6. In the camera switching unit 2, motion recognizing means 4 detects the motion of a movable object from the image of the movable object displayed on the monitor unit 6, and camera switching means 3 performs switching of the surveillance camera unit 1 so as to reference camera setup information 5 to output on the monitor unit 6 a image from the surveillance camera units 1 set up at the destination of the movable object.
In case of that movement of a suspicious person is tracked and monitored indoors or outdoors, a single surveillance camera that is capable of controlling panning, tilting and zooming operations only can track within a limited range. Even when a plurality of cameras are used, a system that detects the motion of a movable object to determine a target camera, information about position and motion of the movable object is lost when a blind spot is present, thus preventing further tracking.
Therefore, in an environment where cameras can be seamlessly set up, such as in a wide place or complicated place, tracking of a movable object is impossible. When a camera has gone faulty, a blind spot also appears, which prevents tracking.
This system must set the alignment of surveillance cameras to determine the target camera. Therefore, it is not easy to move or add surveillance cameras.